The present invention relates to segmenting airways in 3-dimensional medical images, and more particularly to a system and method for extending branches of segmented airways in computed tomography (CT) lung images.
Computed tomography (CT) is a medical imaging method whereby digital geometry processing is used to generate a three-dimensional image of the internal features of a patient from X-ray beams. Such CT imaging results in CT volume data which is a virtual representation of internal anatomical features of a patient. The CT volume data consists of multiple slices, or two-dimensional images, that can be combined to generate a three dimensional image. CT imaging is particularly useful because it can show several types of tissue including lung, bone, soft tissue and blood vessels, with great clarity. Accordingly, such imaging of the body can be used to diagnose problems such as cancers, cardiovascular disease, infectious disease, trauma and musculoskeletal disorders.
The respiratory system starts at the nose and mouth and continues through the airways to the lungs. The largest airway is the windpipe (trachea), which branches into two smaller airways: the left and right bronchi, which lead to the two lungs. The bronchi themselves divide many times before branching into smaller airways (bronchioles). These airways get progressively smaller as they branch out, until they are smaller than a millimeter in diameter. The airways appear as small tubular objects in CT data sets. Segmentation of the airways within CT images can be a difficult problem due to noise and partial volume effects.
Various conventional methods have been proposed for airway segmentation. All such conventional methods either lack speed, require manual input from a user, or have limited ability to obtain a detailed segmentation by reaching the smallest airways. All of these issues can be limiting factors in clinical applications.